The present invention relates to an aspirating system for caps of sample containers. Such aspirating systems illustratively are used in automated apparatus opening blood sample containers. Blood samples or other body fluids to be analyzed are, in general, contained in glass or plastic tubes sealed by a rubber stop or a screw cap. These sample containers are placed in a conveyor chain and are individually-opened by a gripper, which simultaneously exerts a rotating and pulling motion. The sealing cap/stopper removed in this manner from the sample container is aspirated away and put into a collecting container. The suction system provided for this purpose is substantially the same in concept as industrial suction systems known as vacuum cleaners where a blower is mounted on a reservoir and the suction hookup is connected to the opening device. A blood sample handling system of this kind is known from the German patent document DE 195 17 439.9.
Also, suction systems operating with compressed-air injectors are known for the same purpose. On one hand, such an apparatus requires large quantities of compressed air and, on the other hand, all the compressed air must be filtered to remove aerosols from it Accordingly, equipment costs and scope are very extensive.
The pertinent state of the art incurs the drawback that, on one hand, its suction systems are bulky and, because of the high motor power, also relatively loud and, on the other hand, and precisely with respect to blood samples and other medical samples, filtering can be carried out only insufficiently. Lastly, the known practical suction systems incur the difficulty that the entire collecting container, which at the same time also supports the blower, must be removed from the apparatus when being emptied, as a result of which the serial, automated opening procedure must be interrupted.